.. need current to illuminate, and current usually flows through a power supply to an LED. A typical LED-driver circuit uses a transistor to provide current and a series resistor to ...
.. seen lots of interesting conversations and Design Idea (DI) collaboration devising circuits for power switching using inexpensive (and cute!) momentary-contact SPST pushbuttons. A recent and interesting extension ...
.. a whole” is a very old and often true maxim. For example, it’s almost always true when said about AC phase angle power control. You rarely want significant alternating half-cycle asymmetry due to the (usually undesirable) DC load ...
.. I had a somewhat different triac control requirement calling for two manually operated pushbuttons, one for turning AC power on and the other for turning AC power off while preserving the zero-crossover feature. Another issue was that ...
.. an RS-232C serial line (Figure 1). In low-cost applications that require high voltage insulation, low part count, and low power, you can use consumer components, such as SFH421 IR LED with an SFH320 IR phototransistor. The rise/fall-time ...
.. an interval proportional to its corresponding content of red, green, or blue. During each PWM frame, an LED die receives power for as many as 14 steps per frame as the color map of Figure 2 shows. Although not all LEDs are necessarily ...
.. originally published by Stephen Woodward. These are all designed for DC voltages less than 15 V, since this is the maximum power supply voltage of the CMOS ICs that were used in their design. There are several applications that use 48 VDC ...
.. just a fact, I’m curiously fond of topologies that combine PWM switching and filtering circuitry with power handling devices like adjustable voltage regulator chips. This scheme makes power-capable DACs with ...
.. circuits often derive their power from widely varying sources that can exceed the 40 V maximum rating of popular switching ICs. This Design Idea ...
.. 1:1 ratio between output voltage and resistor mismatch. A possible drawback is the price: instrumentation amplifiers with a power supply of 5 V and more start at about 6.20 USD. Figure 3 shows another circuit using a dual op-amp, which is ...